From Paul Thurrott's winsupersite.comIf a report from Chinese tech blog win8china.com is to be believed--and they've been pretty accurate so far--the Release Candidate (RC) version of Windows 8 will feature a tweaked Explorer user interface that somewhat matches the flat UI that pervades the Metro interface.
Here are some before and after shots that will drive home the expected change:
Before (Beta/Consumer Preview):
This flatter new Explorer is just the beginning, folks. We've learned separately that other UI changes are coming to the RC build, including new icons, new cursors, new controls, and more.